The invention relates to a method for matching adaptive radio subscriber stations to transmission networks having different radio transmission interfaces, and to a corresponding radio subscriber station.
In transmission networks such as the cellular mobile radio network complying with the GSM standard (Global System for Mobile Communication) for example, basic interface information is transmitted in the downlink transmission direction to the radio subscriber stations once the radio subscriber stations have logged on in the transmission network. The interface information in this case passes via signaling channelsxe2x80x94in particular the broadcast radio channel (Broadcast Control Channel BCCH)xe2x80x94of the standardized radio transmission interface to the radio subscriber stationsxe2x80x94see xe2x80x9cGSM-Funkschnifttstellexe2x80x9d [GSM radio interface], by P. Smolka, Telekompraxis 4/93, page 19.
As soon as an adaptive radio subscriber station, which is designed as a multifunctional radio subscriber station for example, wishes to communicate with transmission networks having different radio transmission interfaces, it must be matched in advance to the respective radio transmission interface. It is thus necessary for the adaptive radio subscriber station to receive interface information, for example about modulation methods, the encoding algorithm and service availability. This means that it is necessary for an adaptive radio subscriber station to match its capabilities and characteristics to the respective transmission network before logging on, by loading the corresponding interface information.
The object of the present invention is to specify a method of the type mentioned initially and a corresponding radio subscriber station, by means of which matching to transmission networks having different radio transmission interfaces is possible.
The adaptive radio subscriber station transmits a request to the transmission network in which it wishes to log on, by means of which interface information is called up in order to identify the radio transmission interface of the transmission network. A control device in the transmission network receives the request, evaluates it and passes it on to a data device, by which the interface information is provided. A data link for transmission of the interface information is set up between the data device and the radio subscriber station which receives the interface information in the downlink transmission direction via a data channel of a data service.
The use of a data service, which can be used in the transmission network, for matching the radio subscriber station makes it possible to transmit the interface information via a data channel and not via a signaling channel, so that no additional load for signaling is necessary in the transmission network. The transmission of the interface information via the data channel is carried out only on request from the radio subscriber station, that is to say the radio subscriber station is not continuously supplied with the information via a signaling channel (for example Broadcast Control Channel in the GSM mobile radio network). In this way, none of the useable bandwidth is consumed by the continuous transmission of the interface information.
Furthermore, the invention makes it possible to charge for transmission of the interface information to the radio subscriber station and does not cause any additional complexity in the transmission network, since already existing charging algorithms may be used for the existing data service. The transmission of the interface information in the downlink transmission direction, which is carried out on request, for matching the adaptive radio subscriber station to the respective transmission network is considerably more flexible than providing the interface information via the SIM board (Subscriber Identity Module) which the radio subscriber requires in order to use the radio subscriber station. It would be necessary to reprogram the old SIM board or to purchase a new SIM board when new services are introduced, which also results in additional actions by the radio subscriber. The invention allows the adaptive radio subscriber station to be matched automatically or by manual input to the transmission network with the associated radio transmission interface. In the case of automatic matching, a standardized identification of the radio transmission interface is required between the radio subscriber station and the transmission network, or the radio transmission system of the transmission network.
Advantageous developments of the present invention are as follows:
The transmission capabilities of the radio subscriber station for data services are also transmitted in the request for transmission of the interface information. Before setting up the data link, the control device uses the received transmission capabilities to check whether it is possible to transmit the interface information via the data channel. Before setting up the data link, the control device checks whether a network subscriber who is using the radio subscriber station is authorized to direct to the transmission network the request for transmission of the interface information. If the network subscriber who is using the radio subscriber station is not authorized, or if the transmission capabilities of the radio subscriber station are unsuitable, the request for transmission of the interface information is rejected by the control device, and the reason for the rejection of the request is transmitted to the radio subscriber station. If the network subscriber who is using the radio subscriber station is authorized and if the transmission capabilities of the radio subscriber station are suitable, the request for transmission of the interface information is confirmed by the data device to the radio subscriber station. After the transmission of the interface information via the data channel of the data service, the data link which was set up between the radio subscriber station and the data device is cleared down.
From the plurality of possible data services, that data service is selected with which the interface information is transmitted as quickly as possible.
In the case where it is not possible to clear down a data link via the radio transmission interface of the transmission network to which the request is directed, the interface information is called up by the data device via a substitute data link in another transmission network in which the radio subscriber station has already logged on.
A satellite-assisted data link is used as the substitute data link to the radio transmission interface.
A mobile radio network is used as the transmission network. In mobile radio network the request is directed to a service control point and to a service data point which are linked into the mobile radio network in order to handle services, based on the network structure of an intelligent network.